Reputation mechanisms help peers in a peer-to-peer (P2P) system avoid unreliable or malicious peers. In application-level networks, however, short peer life-times mean reputations are often generated from a small number of past transactions. These reputation values are less "reliable," and more vulnerable to bad-mouthing or collusion attacks. We address this issue by introducing proactive reputations, a first-hand history of transactions initiated to augment incomplete or short-term reputation values. We present several mechanisms for generating proactive reputations, along with a statistical similarity metric to measure their effectiveness.
Gayatri Swamynathan, Ben Y. Zhao, Kevin C. Almerot